The subject matter described and/or illustrated herein relates generally to electrical connector systems and, more particularly, to electrical connectors that are mounted on circuit boards.
To meet digital multi-media demands, higher data throughput is often desired for current digital communications equipment. Electrical connectors that interconnect circuit boards must therefore handle ever increasing signal speeds at ever increasing signal densities. One application environment that uses such electrical connectors is in high speed, differential electrical connectors, such as those common in the telecommunications or computing environments. In a traditional approach, two circuit boards are interconnected with one another in a backplane and a daughter board configuration. However, at the footprints of the circuit boards where the electrical connectors connect thereto it may be difficult to improve density while maintaining electrical performance and/or reasonable manufacturing cost. For example, in known circuit boards, vias within the circuit boards are plated, creating plated through holes (PTHs) that are electrically connected to corresponding traces in the circuit board. Contacts extending from the electrical connectors are connected to the PTHs, and thus the traces, using eye-of-the-needle contacts. However, the PTHs create electrical problems, such as low impedance and high cross-talk through the circuit board. One method of improving such footprints is to counterbore a portion(s) of the PTHs to remove the plating to an area just in the vicinity of the corresponding trace in the circuit board. However, the same problems still remain in the short length of the non-bored PTHs that remain for interfacing the contacts with the traces. Such region, though short, still has low impedance, which becomes increasingly problematic at higher transmission speeds.
At least some known systems have attempted to eliminate the plating entirely in the vias, having the contacts connect directly to the traces. However, such systems are not without disadvantages. For instance, there are significant stresses placed on the contacts as the contacts are inserted into the vias, resulting in contact wear and/or buckling of the contact. To overcome such problems, the contacts are made larger, which may cause additional signal degradation problems. Additionally, such systems utilize contacts that are relatively short, which limits such systems to circuit boards that are relatively thin, or restrict connection to an upper layer of the circuit board.
To achieve higher system densities and speed, further improvement of circuit board footprints and connections to the circuit boards must be made over known approaches. There is a need for an electrical connector that enables improvement of the density and/or electrical performance of circuit board footprints to achieve higher system densities and/or higher system speeds.